Introducing LSAT Logical Reasoning – The Terrain @LSATPreparation

Introducing LSAT Logical Reasoning – The Terrain

A study of arguments should be part of any LSAT preparation course.

Introduction – What Skills Does The LSAT Test?

The LSAT is a test of reading and reasoning in context. Your reading and reasoning skills will tested in the broad  contexts of:

LSAT Logical Reasoning

LSAT Logic Games

LSAT Reading Comprehension


The Format Of Logical Reasoning

Logical Reasoning consists of two of the four scored sections on the LSAT. Each section will have approximately twenty-five questions. For this reason many people  say that “Logical Reasoning”  is fifty percent of the LSAT. No, reading and reasoning is one hundred percent of  the LSAT.

Part I – Nature Of The Stimulus – Mostly Premises and Conclusions Which Equal Arguments

Most of the questions are based on “arguments”. What does LSAT mean by the word argument? According to LSAT arguments are:

“… sets of statements that present evidence and draw a conclusion based on that evidence.”

Now, a bit of vocabulary:

Premises: The  statements that present evidence, which are offered as justification for the conclusion, are called “premises”.

How does one identify premises? What is the language of “Premise Indicators”?

Words like “because”, “since”, “for the reason that”, etc., do indicate justification. For that reason they are often indicative of “premises”.

On the LSAT, all “premises” are offered as being true. There is no attempt to justify or support them. Hence, when answering LSAT questions, one must assume that premises are true.

Conclusion: The main point – the position that the “premises” are in support of  is called the “conclusion”.

How does  one identify a conclusion? What is the language of “Conclusion Indicators”?

Words like “hence”, “therefore”, “thus”, “it follows that”, etc., indicate a “conclusion”. For this reason they are often “conclusion indicators”.

(A word of caution: since arguments can have multiple conclusions, a “conclusion indicator” may not be an indicator of the main conclusion! It may be an indicator  of  an intermediate conclusion. An intermediate conclusion could  be a premise for a main conclusion.)

In contrast to “premises”, “conclusions” are not assumed to be true. They are offered as being somehow justified by the “premises”.

Getting A Bit Ahead Of Ourselves For The Moment – Two Additional Points About “Premises” and “Conclusions”

First – it is a mistake to think that the “conclusion” or “premises” appear in any particular location in an argument. For example, although the “conclusion” is often at the end, it doesn’t have to be.

Second – arguments may have more than one conclusion. The first conclusion may actually operate as the a premise for a second conclusion.

The extent to which the “premises” justify the “conclusion”, is NOT ASSUMED, but is open to challenge.

It is the analysis of the relationship between the premises and the conclusion that is at the heart of most of these questions. LSAT calls this the process of evaluating:

“How The Argument Goes”.

Part II – What Are You Asked To Do With The Arguments? Determine “How The Argument Goes”

“How The Argument Goes

Once you have identified the premises and the conclusion, the next is to get clear about exactly how the argument is meant to go; that is, how the grounds offered for the conclusion are actually supposed to bear on the conclusion. Understanding how the argument goes is a crucial step in answering many questions that appear on the LSAT. This includes questions that ask you to identify a reasoning technique used within an argument, questions that require you to match the patterning of reasoning used in two separate arguments and a variety of other question types.

Determining how the argument goes involves discerning how the premises are supposed to support the overall conclusion.”

– page 16 “The Official LSAT SuperPrep.”

(“The Official LSAT SuperPrep is published by Law Services is among the best LSAT prep books.

You will notice that this is very non-technical language. That is deliberate. LSAT cannot use language that would require a specific academic background to understand.

“How The Argument Goes” and Answering LSAT Questions

LSAT questions consist of an argument, question and answer choices. Hence, we must consider what “how the argument goes” means in relation to  each of these three components.

Component 1: The Argument or Passage;
Component 2: The Questions;
Component 3 : The Answer Choices

Every question involves analyzing the interplay among these three components.

Component 1: LSAT Logical Reasoning Arguments – What Are They About?

Job 1 – Identify The Components Of The Argument – The  “What” and the “Why”

The Four Steps To Reading an LSAT  Argument:

1. Where is the main point or conclusion?

2. What is the main point/conclusion that is being made?
3. How far does that main point/conclusion go? What is the subject of that main point (beware of answer choices that are too broad or too narrow)?  What exactly is being said about that subject (again beware of answer choices that are too broad or too narrow).
4. Why? What is the justification/premise for the conclusion? What is the  premise that is offered to support the conclusion?

Note that LSAT arguments almost  always contain information that is neither a premise  nor  conclusion.

In summary: when you read the argument one must determine:

What is being said and why?

Job 2 – How Does The Argument Go? – The Basic Skill

Okay, you have identified the components of the argument.

Job  2 is to determine “how  the argument goes”.

You must consider  exactly how the premise is supposed to support the conclusion – i.e. identify “how the argument goes”

If the passage is NOT an argument you must be able to understand the primary purpose/main point of the passage.

Component 2: LSAT Logical Reasoning Questions – What Are They About? Question Types vs. Question Groups

To repeat the directive from LSAT:

“Once you have identified the premises and the conclusion, the next is to get clear about exactly how the argument is meant to go; that is, how the grounds offered for the conclusion are actually supposed to bear on the conclusion.”

LSAT questions ask you questions about “how  the argument goes”. When reading the question you must understand what aspect of “how the argument goes” are you asked to respond to?

Many LSAT preparation books and courses focus on the categorization of Logical Reasoning questions. Your job is NOT  to  put questions into categories. Your job IS to understand what aspect of  “how the argument goes”, the particular question asks you to focus on.  Examples include questions that ask:

– what would strengthen or weaken the linkage between the premises offered as support for the the conclusion and the conclusion itself

– what is required to be added to the premises in order to ensure that the conclusion follows

– what, although not required as a premise, if added as a premise, would  guarantee that the conclusion follows

– what label or  cluster of  words, accurately describes the method that the argument uses

– what is a general principle that would  justify the conclusion and/or how the premises bear on the conclusion

– what is an example of a question that uses the same format or methodology as the argument in the question

– what is an example of an argument that is flawed in the same way as the argument in  the question

There are many different aspects to the “how the argument goes” issue. It is always easier to think in terms of smaller groups than larger groups. The large number of questions types can be broken into a smaller number of question groups.

Although there is considerable overlap, the vast majority of the actual LSAT questions fall into one of five groups.

Group 1 – Objective Description

These questions will ask you to identify:

– the method or reasoning used in arguments; or
– the pattern of reasoning used in arguments (parallel reasoning);
– matching and identification of argument flaws;
– questions that ask you to identify what the conclusion of the argument actually is;
– questions that ask you to identify points on which disputants hold the same or conflicting points of view;

Group 1 questions ask you to identify objective aspects of the argument but do not require you to make a judgment about its persuasive value.

Group 2 – Effectiveness And Persuasiveness – Questions That Ask You To Identify What Would Make The Argument More Or Less Persuasive

These questions will ask you to assess:

– what additional information would make the argument more or less persuasive (strengthen or weaken how the premises bear on the conclusion). These questions usually do NOT ask what would guarantee that the conclusion would follow from the premises.

Group 2 questions will require you to assess the persuasive value of the argument. They often use the language “strengthen” or “weaken” the above argument? They are related to Group 4 questions, which often use the language of “assumptions”.

Group 3 – Questions That Ask You To Determine What Follows From The Argument Or Passage

These questions will ask you to determine:

– what further inferences can be made from the passage or argument (note that the strength of the inference is important. Are you asked to determine: what ALWAYS follows from, what SOMETIMES follows from or what NEVER follows from).
– The applicability of “sufficient” vs. “necessary” conditions. (These topics are tied heavily into the analysis of conditional reasoning.)

Group 3 questions may or not be based on arguments and require you to choose an answer choice that extends beyond the argument.

Group 4 – Questions That Ask You To Identify What Additional Information/Premise Plays A Role In Ensuring The Conclusion Must From The Premise(s)

These questions will ask you to:

– identify the REQUIRED missing premise: the premise that must be added to guarantee that the conclusion MUST be true  (Some commentators refer to these as “necessary condition assumptions);
– identify a premise, that although NOT REQUIRED would be a GUARANTEE that the conclusion would follow (some commentators refer to these as sufficient conditions assumptions)

Group 4
questions are related to Group 2 questions but often use the language of “assumptions”. Group 2 questions often use the language of “strengthen” or “weaken”.

Group 5 – Questions That Ask About Principles

These questions will ask you to:

– identify a principle that will govern a situation;
– apply an existing principle to a given situation.

Component 3: LSAT Logical Reasoning Answer Choices – What Are They About?

This is where the action is. The LSAT is multiple-choice. Your job is to recognize or identify the answer. LSAT will not make this easy. In fact, the job of LSAT is to:

“Attract you to answer choices that are wrong, and repel you from answer choices that are right!”

To facilitate this goal, LSAT has developed a large number of disguises. Some of these disguises are based on content, some are based on application and some are based on format. What follows are some comments on each:

Content Based Disguises – Some Examples:

– answer choices that include too much or too little;
– answer choices that require meeting multiple conditions when not all of the conditions are met

Format Based Disguises – Some Examples:

– the order of the answer choices – attractive wrong answer distractors appearing before the right answer;
– the ordering of information in a specific answer choice – putting irrelevant information before the part of the answer choice that matters.

Application Based Disguises – Some Explanation:

In my experience theses are by far the hardest for students to see. Although you must  read the language of the answer choice very carefully, you must go well beyond that careful reading of the answer choice.

Ask yourself:

If the information in this answer choice were true, how would that affect the answer to the question being asked!

Our LSATtutoring.com Tutorial Series has been designed to explore may of these topics.

We offer full-length Toronto LSAT Preparation Courses

Copyright © 2006, John Richardson. All Rights Reserved.

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